The research is concerned with autonomic regulation of growth responses and secretory activity of salivary gland. It is now known that growth responses in salivary gland can be evoked, or suppressed, by alterations in the extent and duration of secretory activity and that these effects are mediated through glandular autonomic receptors. It is planned to investigate the nature of this link. A first step will be delineation of the type of autonomic receptor involved in mediating specific growth response. Techniques of selective denervation as well as the use of autonomic antagonists will be used. Secretory activity is to be investigated mainly with regard to inorganic components of saliva. Emphasis is to be placed on secretory events in the salivary duct system, and their regulation by the autonomic innervation. For this, perfused main excretory duct of rat submaxillary gland will be used as a model system. Net fluxes of electrolytes across the duct, as well as transductal PD, will be measured in this perfused system, and the influence of autonomic stimulation of the duct cells on these parameters will be examined.